I purchased this top about three years ago now and still there is no sign of wear. It has had a lot of use, from light hill walking to climbing Little Tryfan in Wales. So apart from the brilliant quality, this top has three other reasons to justify £60 on a mid layer: fit, warmth and versatility.
First the fit, it is body hugging, so if you don’t want the next to skin feel then buy a size larger than what you would usually have. However the 4 way stretch of the Polartec material is fantastic, the top won’t rise up when reaching for your next climbing hold, and the thumb loops are great for when it turns really chilly.
Next there is the warmth. I've often been comfortable enough in -2C with just this and a base layer on underneath. Once you get moving, the Rab fleece really keeps you warm, and the massive zip offers really good ventilation. Again with the stretch, if you are overheating, you can pull the sleeves up easily.
Lastly is the versatility, like I've mentioned before I've used it for climbing, walking, general day wear and even running. The Rab Power Stretch Zip Top is designed for winter use, but you can use it on its own in the summer (it just isn't the greatest of looks when the zip is completely undone!).